CHARLOTTE, N.C. — As he took the stage to thunderous cheers Thursday night, as he kissed his wife and settled the crowd to deliver a speech that might just help save his shaky presidency, Barack Obama's task was easier than Mitt Romney's a week ago in Tampa.

Unlike his Republican pursuer, Obama didn't need to spend much time "humanizing" himself. Even many people who don't like his politics or policies already believe he is a good and decent guy.

Unlike Romney, Obama didn't need to bring together the various factions of his party or prove to any one that he can be trusted to represent them. If the Democrats weren't already energized by what they believed to be distortions and deceptions in Tampa, Obama and his surrogates revved up the party faithful — regardless of ideology — to hit the streets hard for their standard-bearer.

Unlike Romney, Obama didn't have to worry about looking or sounding presidential. Obama already is, enjoying all the priceless perks and privileges the position commands. When Obama talked about foreign policy, an area where voters see him as successful, he spoke with the authority of a commander in chief who ended a war and ordered the deaths of our deadliest enemies. Osama bin Laden didn't even need to be named.

And unlike Romney, Obama had Bill Clinton, whose speech Wednesday reminded us that nobody in the Republican or Democratic parties comes close to his effectiveness as a personal and political validator.

Clinton's special strength was — and evidently still is — the ability to sell himself and his party to moderate swing voters. In 1992, as the suburbs were developing into the nation's decisive voting bloc, Clinton created a new middle-of-the road map, more socially moderate and fiscally conservative, that made the Crabgrass Frontier safe for Democrats who would follow it.

On Thursday night, Obama showed he understood and accepted Clinton's approach to these swing voters. Channeling Clinton's 1992 acceptance speech, Obama declared that "not every problem can be remedied with another government program or dictate from Washington."

The Democrat's Great Communicator, Clinton helped Obama by delivering both red meat and sweet tea in attacking the Republicans and defending his own party and the President. He took on two of the GOP's heretofore most effective talking points: that we are worse off now than we were four years ago, and that "Obamacare" has been an expensive failure.

Clinton made things easier for Obama by asserting that we are better off — that we were losing 750,000 jobs a month when Obama took office but are now creating jobs and profits, especially in the auto industry that the President bailed out over Republican resistance. Clinton put Obama's health care plan in personal terms for people and business owners, especially how it benefits, or soon will benefit, people who already have health insurance and those whose coverage is inadequate or non-existent.

As a result, Obama didn't need to spend a lot of time on the defensive about these and other issues; he could talk more about the future that voters care about most.

Obama needed to take advantage of Clinton's at once bitingly and soothingly effective defense of the past and focus his message forward. And so he did. "The path we offer may be harder, but it leads to a better place," Obama said. "And I'm asking you to choose that future."

In asking for four more years to make things right, the President needed to give voters more than vision; he needed to spell out at least some details of what he wants to do in the next four years.

He outlined a plan to cut the deficit by $4 trillion in a decade and hire more math and science teachers and slow the growth of college costs. "I'm asking you to rally around a set of goals for your country — goals in manufacturing, energy, education, national security and the deficit," Obama said. "A real, achievable plan that will lead to new jobs, more opportunity and rebuild this economy on a stronger foundation."

This was Obama's night; he was on his own now and needed to be straight with voters. "You elected me to tell you the truth," Obama said, tacitly acknowledging that believability is more essential than liability. "And the truth is, it will take more than a few years for us to solve challenges that have built up over decades. It will require common effort, shared responsibility, and the kind of bold, persistent experimentation that Franklin Roosevelt pursued during the only crisis worse than this one."

This convention can only be seen as successful for the Democrats, even below the top of the ticket. And in its final moments, Obama did what he needed to do to keep the momentum moving forward.